The sweet orange, Citrus sinensis, of the Rutaceae family, is the most important citrus fruit. The United Nation Food and Agriculture Organization ranks world orange production first among the tree fruits, with the apple next. Brazil, United States, China, Spain, and Mexico are among the major producers of oranges.Orange grow on medium sized evergreen trees, which under favorable conditions may yield fruit for 60 years or more. The pungent leaves have a glossy, wax-coated surface. The small white flowers, which are borne in clusters, appears in the spring in the subtropics but throughout the year in some tropical climates.
Botanically, the fruit is a berry known as a hesperidium. Oranges are round to ovular and covered by a thick, leathery peel that turns yellow orange to deep orange when ripened in subtropical climates. In the tropics ripe oranges are usually green to pale yellow. The inner pulp (endocarp) consists of 9 to 16 segments filled with juice vehicles. Ripe oranges normally contain 35 to 50 percent juice by weight, depending on variety, climate, and cultural conditions. Oranges may be seedless (navel), nearly seedless, or seedy. Extracted juice usually contains 9 to 12 percent total soluble solids (mostly sugar and citric acid); each fruit contains 20 to 60 mg (a small fraction of an ounce) of vitamin C.
Oranges are either eaten as table fruit or processed into related products, the most important being frozen juice concentrate. Other products are chilled and canned juice, canned sections, and dehydrated powder. The peel, seed, and pulp by products of juice production are used in cattle feed, molasses, and special products such as peel oil.